Navigational instrument.



, E.YA. SPERRY. l NKAVIGAIIONAL JNSTRUMEN. APPLICATION FILED FEB: 3. 191.5.

Patented Apr. 15,1919.

' 4 SHEETS-sumar).-

I-E. A.l SPERRY NAVIGATIQNAL INSTRUMENT.

APPLICATION FILED FEB. 3. 1915.

Patented Apr; 15, 1919.

4 SHEETS-SHEET 2.

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-/MER' H. 511m? Y.

.Y E. At ASPERRY.` NAvlG-ATl-OYNIAL g'NsTRuMENT.

APPLICATION FILED FEB. 3| |915.

Patented Apr. 15,1919

` INVENTOR @WFM SPQR/.YY

mann enanas rara' carica.

ELMEB A. SPERRY, OF BROOKLYN, NEW YORK,` ASSIGNOR TO THE SPERRY GYB'OSCOPE COMPANY, OF BROOKLYN, NEW YORK, A CORPORATION OF NEW YORK.

NAVIGATIONAL INSTRUMENT.

Lacasse.

I To allfwwm it may concern.'

Beit known thatl I, ELMER A. SPERRY, a citizen of the United States of America, residing at Brooklyn, N. Y., have invented certain new and useful Improvements in Navigational Instruments, of which the followingis a specification.

The invention relates to precision instruments in which the directive4 power in the position of equilibrium is small, but in which great accuracy is required. More specifically my invention relates to means for increasing the accuracy and sensitivenessof the gyroscopic compass, although it'will be evident that the means I provide may readily be used on other types of precision instruments. A further object of my inven-v tion is to improve the means by whichqthe readings of the-master compassare transmitted to the repeater compasses.

What I now consider to be one of the preferred forms of my invention is shown in the accompanying drawings, in which Figure 1 1s a plan view of the master compass, parts being broken away to show the operating mlechanism.

Fig. 1av is a fragment/ary vertical vsection taken on a vertical plane through the line 2 2 of Fig. 1, but looking inra direction` opposite to that of the arrow.

Fig. 2 is a vertical section of the master transmitter on line 2 2, Fig.-1, looking in the direction of the arrow.

Fig. 3 is a detail elevation,

Fig. 3a lis a fragmentary,A detail view Fig. 4A is an elevation mittel", which is switch panel.

Fig5 is an enlarged detail elevation-of" one of the contacts on tbe follow-up'system.`

' Fig. 6 isa detail thereof. N. c

Fig. Tis a section on -line 7-7'of Fig. 2, looking in the direction of the arrow, the

brush64 being shown removed from the position it normally occupies in order toshow lother parts more clearly.

Fig. 8 is a diagrammatic view of al portion of Fig. 4:.,

Fig. 9 is a wiring diagram of my complete .p system.

partlyv broken -away of the follow-up motor.

partly in section of .the clutch connections Specification of Letters Patent. Patentd App, 15, 191930 Application filed February 3, 1915. Serial No. 5,819.

Fig. 10 is 'a detail side lelevation of the follow-up relay and contact block forming a partof my invention.

Fig. 1l is a detail rear elevation 4of the lfollow-up relay.

Fig. 12 1s a fragmentary plan view of the vcontact block, certain ofthe parts being a follow-up device-2=which supports said sensitive element. The follow-up device' '2 is rotatably mounted-'in the spider 303'by means of bearings 305 and su 4ports the sensitive element 1 by means of the torsion wire 306 secured to the follow-up device at 500.

The follow-up device carries also, theNcompass card v3 adapted to coperate with the lubber ring-307 carried by the spider. The sensitive element 1 comprises a vertical ring 308 suspended at the lower endvof the torvsion wire 3,06 vand guided by a. vertical bearing 810 at the top` and a similar bearing at thel bottom' (not shown). Said element has pivotally connected theretov the' gyro Case 309A which rotatably supports and incloses the gyro rotor 310 adapted to be electrically driven by the stator 311. The follow-up device, besides carrying the. compass card `3, is adapted to actuate whatever mechanism is used to transmitfcompass readings to various parts of the ship. The specific obvject of the present-,invention is to improve upon themechanism of the follow-up system'andV for this reason further detailed description of the` gyro-compass is unnecesgyrocompass both' as to structure and Operation lmay be hadvby referring to my two prior applications 634,594 and 634,595 iiled June 21, 1911. VIt should also be borne inmind that my invention may be applied to of apparatusi'than herein illusother forms trated.

The principal `purpose of the follow-up system is to relieve the sensitive element4 of sary. A more detailed. description of the vthe necessity of ldoing work during its apparent arc-in-az'imuth movements'. `The cause that gives rise to themost trouble in this regard is friction about `the vertical axis. tirelyeliminated.

Risingv from the sensitive element areA posts 5, which pass through slots ork openings 6 in arms 7 of the follow up system, and which carryl adjacent their upper ends parts of contact vdevices.v Preferably these parts v are inthe form of brushes or trolleys 8.

, On' the follow-'up system coperati'ng contacts 9 'are placed. Each contact comprises a palr of conducting stripsl() and 11,

.separated by an air gap. One or both of the lcontacts are preferably made adjustable in azimuth, as shown in Figs. 5 -and 6. Each contact is mounted on an adjustable strip v12, provided adjacent each end. with clongated holes. 13 and at one end with a transverse' slot 14.l Posts 15 and 16 project up piece 12 with its connected parts ,may beY s0v position after adjustment.

from the base .17, the former being elongated and .surmounted by a 'knurled nut 18. A sleeve 19 is fittedv 'loosely on post 15, and is adapted to be clamped between nut 18 and `the base 17. The-lower end 91', of said sleeve is eccentric, and fits in slot 14, so that adjusted longitudinally by rotating sleeve 19.. Nut 18 is'used to clamp the parts in By this or equivalent means thje.A two contacts can be alined or thrown out of alinement for pur-'y poses hereinafter described.

According to -my -prior-lapparatus, the

follow-up motor A20, which turns the followup device, was placed directly in circuit with these contacts, which arrangement is illustrated in Fig. 9 when the switches 100, 265

V are closed and the relay 21 removed, the action of the device being that the trolleys would normally stand between the-contacts with the whole system at restuntil the ship turned, when, apparently, each trolley would move on to one contact and start the followup motor. It will'be seen that as soon as the" motor is started, friction about the vertical axis will be practicallyI eliminated,'but I have discovered that with this device before the motor is started,.considerable friction may arise, due doubtless to the entire work of moving the contacts and sensitive element,

initially, with respect to the follow-up `system against what may be'termed the relatively large static friction of the bearings andother parts falling on the sensitive element. j 4

To eliminate this trouble, I provide` automatic means to prevent the sensitive element.' and its support from. coming to a condition of. completelrest; Preferably I cause a continuou's oscillation ofthe entire'follow-up lsystem through a small arc, so that the` troll leys move rst to one contact and then to the By this invention the friction is en' bearings and elsewhere is 'thrown entirely on the follow-up motor. Not only is friction eliminated thereby, but a great advantage accrues to the observer,'since the' constant' hunting vaction of the compass card produced. thereby serves to attract and hold his attention and furnishes a ready indication to him that the-compass is operating properly.

.My preferred means of'causing this hunting oscillation or vibration is by placing a double relay 21 between the contacts 9 and the motor 20 (see Figs.' 1 and 9).' This relay comprises two electro-magnets 22 and V23, the former being in circuit with contact strips 10, while the latter is in circuit with. contact strips 11. One contact of a switch 24- or 24y is mounted adjacent each end of a pivoted armature 24, so that on one of the magnets beingl excited a circuit is made through the corresponding differential field' coil 25, and the armature lof motor 20, thus causingthe motor to be revolved in the proper direction. Thus, if trolleys 8, 8 are in contactwithcontactstrips 10,110 a circuit is formed through magnet 22 as follows: Starting with battery 1 05, through wires 200, 201, 203 (or 203') trolley j contacts 10, wire 204 (or 204.)', magnet 22,

wires 205, 206, 207, 208 and back to battery 105.

Closure of the .last mentioned circuit causes the magnet 22 to attract one end of the centrally pivoted armature 24 causingv switch 24 to close the following circuit. Starting with battery 105,y through wires '200, 201, 202, 209, 210, 'switch 24, wire 211, wire 212, one of field windings 25, wire 213, armature of motor 20, coil,34, wires 206, 207

and 208,'and back to battery 105. Excita-' tion of the other magnet will cause the reversal of the motor, as vwill be readily apparent. The armature 24 is centrally pivo'ted so that both contacts can not be closedat the same time so that a continuous reversing of the motor is caused as long as the position of the compass is fixed` in azimuth.' 'Connected across the spark gaps of the contacts.

The magnitude of the oscillation imparted to the follow-up device can readilybe adjusted by means of the adjustable contacts two contacts 9 arel diametrically opposite each other. The effect of shifting vone con'- tact 9 to a cally opposite the other contact 9 is to cause. the follow-upy motor 20 to move the trolleys.

8 farthert'o each side ofthe central position before said trolleys are on strips which are designated by Vthe same reference vnumeral 10 or 11.l -The relay 21 will prevent the` osition where it is not diametri- 8, either of i densers 27 to reduce sparking,ma'y be con- 9, the movement being a minimum when the i' f motor from becoming locked or from stopping, even if one trolley 8 should be lmoved far enough so that during the oscillation a 'period occurred. in which lone trolley is on one contact y(10 for instance) while the otheris on the opposite contact (11), since, if magnet 23 is energized while 22 continues to be energized, centrally pivoted armature 24 will remain attracted by magnet 22, as the magnetic flu-X is greater through the nearer portion of the armature. l(See Fig. 11.)-

Rotation is transmitted to the `follow-up system from the motor 20 by means of a large gear 28 .mounted .beneath the scale 3, and reduction gearing on the motor 20, compri'sing a pinion 39 on the motor shaft, gears 30 and 31, and the gear-32 with its attached pinion 33 which meshes directly with the .large gear 28 (see Figs. 1 and An elec- 'tro-magnetic. clutch -is connected -with this gearing, which is designed to detach the system from the follow-up motor 20.0n failure on the supply source. This comprises'l an electro-magnet 34, the armature 35 of which formsua lever connectedthrough link 135 with an irregularlyshaped lever 36. Said lever is pivoted to the frame at 37 .and is pinned adjacent one end to a collar on the hub of gear 30, loosely mounted on'v the shaft of pinion 31 (see Fig. 3A). Pins 38 are provided on the opposite side of gear 30 to enl gage the notches in a toothed 'wheel 29 at-` tached to pinion 31.. Electro-magnet 34 normally holds the pins 38v in ,engagementy with Wheel 29, so thatthe motor is connected with gear 28, but as soon as the supply current fails, the Amagnet .will .be denergized and spring-40 will disengage'the clutch. The importance of this feature will be exs y plained hereinafter.

As' pointed out above, the entire follow-up system is rapidly oscillated by continually reversing motor 20. In order to cause as little shock to the parts as possible and to conne .the extent of the oscillation 'within limits, Ilprovide a' novel device located preferably. on the motor. shaft, which I term a friction-inertia device. comprises merely a small fly wheel 41 loosely mounted on the motor shaft, and resting normally onthe friction face 42 of a collar j 43 pinned to the shaft. By this means I provide a friction-'inertiabrake which will connected to one of the slip rings 57.

In construction, it

transmitter173, which may be placed at a distance thercfrom, preferably on the switch panel. This z-ivstem is especially designed to provide means to transmit accurate readings without reproducing the hunting action of the follow-up device described above, in the repeaters. Preferably, said system is made adjustable, however, so that more or less of the vibrations may be transmitted if desired. Transmitter 50 is preferably attached so that it is rotated from the gear 28.' It coniprises a pinion 52 meshing with the gear 28 and secured to a shaft 53 which is supported in suitable bearings 54 and 55. Adjacent the lower end of the shaft is secured a disk 56 of insulating material, which is provided with a-pair of slip rings 57 on its upper surface adapted to receive current through brushes 58. 'Oni thelower surface of the disk are secured a pair of contact segments 61 and 62, each segment being electriclly ne of the strips of insulation 63 separating the ends of. the segments is of considerable breadth and tapers outwardly for a purpose that will presently appear. The hub supporting said disk56 is made v vith a concentric aperture 59Iin its lower end, which serves asa bearing for the upper end of a second shaft 60. p

Secured to shaft60 is an arm 63 which carries a brush 64.adapted to contact with- -radially adjustable by slidably mounting the` otherend of the ybrush in a groove in the holder 63.- A rotatable thumb button 66 is provided withfan eccentric pin 67, which enters a slot .68 in the brush, by means of which the position of the brush can be varied at will. Brush 64 is rotated by means of a repeater motor 69' through suitable reduction gears, such as 70 and 71, the latter being mounted on shaft 60. A brush 72 normally bears on the hub of arm 63 to lead the current to or from the brush.

In circuit with the brushes 58 is a reversi-` ble motor 73, forming a 'partof the relay transmitter shown in Figs. 4 and 9. -This Vmotor has'oppositely wound ield coils 74 and 75, similarto the follow-up motor, each coil. .being in circuit with one of brushes 5K8,

so that the motor is driven in one direction when brush 72 is on segment 62 and is reversed on segment 61, being brought under the brush. Dead section 63 furnishes a section where motor 73 will remain atrest and becomes the means for preventing hunting I beyond the normal will cause a Contact and operate the motor 73, but so that the normal.

hunting action will not /be transmitted. This adjustment in connection with the. adjustment 'of the amplitude of oscillation of the follow-up device, also furnishes-a ready means of transmitting the vibrations of the vdevice to the' repeaters, to a greater or less extent as desired, as will be readily apparent.

Motorl 73V furnishes the power for operating the transmitters proper, which sendy theirI impulses directly to the repeating 1nstruments 84 and v120. It is preferably placed on the switch panel and forms with the connected transmitters the instrument I term the relay transmitter. It is shown as geared to two transmitters 174 and 175 adapted to operate at different speeds.

That is, transmitter 174 is used to actuate in-x f "struments of ordinary calibration, while transmitter 175 is used tov secure a much liner degree v o'f accuracy. The latter 1s shown as mounted on the shaft of gear 76,

driven'by the motor pinion 77,l while .thev

former is driven from gear 78 which meshes with apinion 79 von theshaft of gearl 76.

The actionv of transmitter 174 is; shown sented by 84.j

Transmitter 175 comprises a rotary three vsection commutator 85, provided with a common return section 86. Each section has' ay conducting segment of about 180 arc.

Brushes 90 and 91 are placedl diametrically.

opposite and make contact-with each section,

, While a single brush 97. bears on section 86.

In circuit with eachpair of brushes 90 and 91 is a vibratory ,Contact member87! 1 (see Fig.- 8) comprising' two stationary con? vtact pieces 88 and 89, each in circuit with: one of said'brushes. pieces is a finger'92, designed toberapidly Pivoted between these vibrated by a roller 93 mounted on a' spring pressed arm)94, which may be reciprocated by a cam 95 on the shaft 96.

The parts areso `designed that the operation is substantially 'as follows', assuming that the shaft 96 is rotating in the direction of the arrows shown. in Fig. 8.-' The current isvflowing through wire A, brush 97,

common `return segment 86, segment .320,

' brush 91, contact 88, arm 92to.wire B.

Let us suppose now that theshaft 96. ro tates 90C. The roller 93 slips over the'top lof arin 92. just as it nears its extreme 'left hand position so that'thef spring 93 pulling down on the roller arm snaps the arm 92 over into engagement with contact 89, Thus the above traced circuit is broken at 8 8 with `a quick break. At this vtime brush 90 is on an insulating Segment so that the circuit cannot be closed through' contact `89. Assuming now, that the shaft rotatesthrough another 90o-the arm 92 l is still 1n engagement with'contact 89 and as the brush 90 is nowv engaged by segment 320 l 90o of the-'shaft 96 takes place. The roller 93 then rides over the top of arm 93 as the former-is traveling to the right and breaks the circuit at 89 with a quick-break, the arm 92 then-engaging the contact-88. vAlthough' the last named Contact is in engagement with arm 92 at this point, the brush 91 is in the middleof the insulatingsegment so that no circuit is'made from A to' B until another 4.90"Uturn-.is'made by the. shaft 96. From this description of one cycle it is clearl that there are two. impulses through the circuit A, B, for one/revolution of shaft v96" andl .that each of these lasts approkimately for a quarter revolution.` It will benoted that l' the cricuit is broken at the switch arm 92 thus giving aquick break and: making a greater commutator speed possible. Further -more, it will vbe seen thatwith this arrange' ment the number of impulses per' revolution `is double the 'numberpossible if the commutator alone were used.

While, in describing. the' commutator sections, I vcall them .180 sections, :it-will' be understood that I intend to include all sections Which approach this dimension, it being well known that the exact dimensions are varied' to suit ployed.

. Not only is transmitter 175 used in actuating the repeating instrument 120, but also lthe motor 69 on the master transmitter 50 on I transmitter and relay transmitter 175.

The transmitter 175 is connected through of the repeater motor-120 and through conductors B to corresponding magnets of the repeater motor 69. Thus repeater motors 69 and 120 are connected in parallel with each other and in series with transmitter 175.

Under certain conditions it is desirable to remove the relay'21- Without disturbin the operation of the rest of the system. I, t erefore, provide means whereby when the relay is removed its circuits `are automatically broken and the contacts 10, 11 connected automatically to .the motor circuits, (see Figs. 9 to 12, inclusive). A contact or terminall block 97 is providedon the frame of the compass andcarries terminal plates 250, 251, 252, 253, 254 and 255 each insulated from the others and from v the main portion the thicknessof brush ern- 105 the conductors B to corresponding magnets of the Contact -bleckfand carrying plugs 256 to 261 respectively.' The relay 21 is mounted on a bracket 262 which can be attached and ydetached readily from the contact block 97,

a finger hold or grip 102 being provided to aid in this operation. The bracket 262 carries a series of contact plates 256to 261 each insulated from the others and from the bracket 262 and each provided with a hole respectively while the contacts 100 are eachy 263; The holes 263 form sockets into which the plugs 2,56 to 261 are adapted to enter, thus connecting the plates 250 to 255 to the plates 256 to 261 respectively. By connecting the sockets (256 to 261') to the various relay elements and the plugs (256 to 261) tok the various conductors as indicated in Fig. 9, it will be apparent that I have provided readilyy detachable connections for the relay. It will be noticed ythat all of the plates 256 to 261 are identicalV except the t'wo end plates, which are each shown as provided' with bent-over end portion 99, which each carry one of the contacts 24 24". When the relay 21 is removed and consequently disconnected the members 10 and 11 should each be connected directly to the circuits of the motor'in order that the operation of the system be uninterrupted. While this function might be performed by a separate manual operation I prefer to provide means whereby it is accomplished by theV withdrawal of the relay 21 from contact block 97. For this purpose I provide each of the plates 251, 254 with a contact 265 and a spring contact 100.

Each ofthe contacts 265 is connected by its plate 251, 254 directly to members 11 and 10 connected to a corresponding motor ,(20) field lead (See Fig. 9). Thus each member 10, 11 is connected to the corresponding field said relay in position.

For operating all of the above described mechanism, including the gyro-wheel itself, but two circuits are used, a three phase A. C. circuit for the induction motor 311 of the gyro, and a low voltage D. C. circuit for all of the other instruments. While it is important that neither supply should fail, it will readily be appreciated that the followup system shouldbe made, if anything, more` infallible than the gyro-wheel itself, since the gyro will maintain its rotation and perform its functions several hours after the power is shutoff, while without safeguards a failure in the followlup system would immediately result in throwing the compass readings, and, in a short while, the compass,

itself, off the meridian. To prevent such failures, I provide a storage battery 105 which normally floats on the line, but which assumes the entire load onfailure of the D. C. supply. Areverse current relay 106 serves. to prevent the battery 'discharging back into the line. An alarm Acontact 107 is also operated bysaid relay so that the operator is immediately notified of the failure of the D. C. supply. Additional safeguards are provided on the compass itself.

The construction and operation of therelay 106 is substantially as follows. The relay is made up oftwo coils lor windings 106, and 106, the former of which is adapted to be c'ut into and out'of series with `thepositive side of the D. C. line (see Fig. 9) while.

the latter is connectedpermanently across said line. If the source of direct current is at sufficient potential to charge the battery 105 the coil or winding 106 is energized to suffil cient strength to close the front contacts 400 so that the D. C. supply charges the battery and also supplies energy to the main line throughout the system, as indicated in heavy lines in Fi g. 9. v When front contacts 400 close,'

the coil 106 is energized to aid the coil 106 in maintaining the front contacts closed. If.

for-any reason the voltageof the line drops below that. of the battery 105, the current through the coil 106 will reverse so that the last mentioned coil will oppose and weaken -the pull of the coil l106 and the front con- 'tacts 400 open and back contacts 107 close. When the front contacts 400 open, the D. C. supply is cut off' from the'mam line of the system and the latter is supplied by the storage battery 105. This conditionpersists until the voltage of the D. C. supply is high enough to .energize coil 106" to such magnli tude as to close the front contacts 400.

As stated above a marked drop in voltage of the D. C. supply causes the back contacts 107 to close and these contacts on closlng cause the alarm to sound. Thus when contacts 107 close a circuit is formed as follows: Starting with battery ,110' through wires 401, 402, 403, contacts 107,v Wire 404, relay 112 and wire 405 back to battery 110. The ener-4 gization of relay 112 Vcloses front contacts 113 to close a*V circuit from battery 110 through wire 401, bell 111 contacts 113 and wire 405 back to battery 110," thus causing the alarm to sound. O n inspection of Fig. 9 it will be seen that the contacts 108, 109 hereinafter referred to are in parallel with contacts 107 and therefore the former cause energization of the relay 112 and bell 111 in identically the same manner as said contacts 107. .l l

An important feature is the provision of the double alarmcontacts 108and 109 pref- .erablylocated respectively on a post 5 of the sensitive element, and on an arm 7 of the fol- -low-up system. .On referring tolligs'. 1 and 9, it will be seenjthat one set'of these contacts will beclosed and the alarm sounded as `soon as the follow up system falls a predetermined are out of line with the sensitive'element no matter what the causel is.. A further safeguard is the provision of a throw-out clutch described specifically above.

The .importance'ofthese two safeguards maylbe appreciated, when it is remembered that in case the follow-up motor should fail and the ship should bevturned irl-"azimuth, the posts 5 would strike against one end of slot 6, exerting a torque on the follow-up sys- Vetem.l Thus the ends of 'slots 6 acting in conjunction with posts 5.,(see Figs. land 1A) form limit stops to-limit the extent' of relative movement in azimuth between the sensitive element land follow-up device 2.

If no means were provided to throw out motor 20, the friction of the motor bearings and brushes, multiplied many times by ,the reduction gearing 30, 31, 32, 33 would offer a powerful resistance to the apparent movement of the gyro-wheel, causing undesirable precession and. consequent injurious strains on the whole apparatus. With the motor disconnected, however, the gyro is able to carry/ the follow-up card 3 with. it, so that the readings.'remain fairly accurate; The alarm, of. course, is also sounded through contacts 108, 109. The transmission system" is also designed to otter as little resistance as possible to rotation ofthe follow-urp system. That is, the transmitters 174 and 17 5, which are used to actuate directly theI repeater motors, are notmounted on the compass' but are independently` driven from the relay motor 73. The control of motor 73 by master transmitter 50 requires very little power from the follow-up system, especially since motor 69 aids in rotating said transmitter 50. The alarm systemis supplied with a separate battery 11,0', and a bell or other signal 111. A relay 112 may be placed in thecir cuit which operates to-'close a new circuit, upon the closing of one of the alarm circuits, which will remain closed until opened by h and, so that the'lbell when once started, willV ring continuously.- For this purpose a lockingdog 800 is provided to hold the contacts 113 together after they solenoid 112. i

CallingI particular attention to Fig. Q'the operation of my system may be summed up as follows: With the connections made as shown and the sensitive element 1 stationary, the contacts 8, 10 and 11 which are inseries with the relay coils 22, 23 across the main line will .energize one or both of the latter. One or the other of the 'contact sets 24, 24

are once closed bywidth of the insulation 63 the brush 64 does not follow the oscillations of said contacts 61, 62.l Wlhen the sensitive element changes position the contacts 8, 10,.11 acting through` the relay 21Vcause the motor 20 lto -run iI'l such a direction as to cause the member 2 to follow themovem-ent'of the sensitive ele'- ment 1. This movement of member 2cau`ses a movement ofthe contacts 61,- 62 sufficient to move 'the insulation 6?( away from brush 64 so that the latter will be in engagement with one or the other of said contactsv 61, 62. The motor 73 which is in series with brush 64 and contacts 61, 62 across the main line, is thus energized to cause it to rotate -in the proper direction.l The last mentioned motor mechanically drives both of the transmitters 174 and 175. The transmitter 1 74 being in series. with the repeater motor 84, across themain line, energizes said motor to cause it to repeat the movement of said transmitter. Transmitter 175, beingA in series with repeater motors 69 and 120 across the main line, likewisecauses V'these motors to repeat its movement. The repeater motor 69 -acting through gears 70, 71 rotates the brush 64 to cause the latter to follow the movement of the contacts 61, 62. Thus thevrepeater 100 motor 84, 120 and consequently the repeater Compasses' actuated thereby will constantly be positioned in accordance with the position of the sensitive element 1 of the master compass.

If the yrelay 21A is removed, its circuits are automatically broken, as previously described, and the'switches 100 close .automatically. The motor 20 is then directly in series fwith contacts 8, 10,311 and therefore directly 1"10 controlled thereby. The operation, under this condition,` is essentially the same as that above described except that relay 21 no longerl enters into the operation. A

Should'the D. (lvmain line become dead 115 the relay 106 functions to close its back con- Y tacts 107 to cause energiz'ation of the alarm 111 (asfpreviouslydescribed), to warn the operator." Under this condition, the battery 105 supplies energy to the main line.

Any failure of the main supply between batteryI 105 and motor 20 will cause dener-' gization of coil-34 to disconnect said -mot'or from the follow-up 2, thus allowingthe sen-v sitive element 1 te move the latter with vcom- 125 paratively small exertion of force. The la'st mentioned actuation takes place through. posts 5 andthe walls'of slot 6 and it will be clear that under this"` condition the contacts 108 and 109,close to cause the alarm 111 to" l apprise the operator of the above mentioned failure. 4

Inv order that the contacts 10 and 11 may be readily replaced or vertically adjusted to present a new wearing surface, they are made in the form of a little block 110, with a linger hold`111, andA with holes in the bottomto engage over resilient studs 112, rising from plates 113 which are secured to piece 12, referred to above.

It should be noted that in the 'normal operation the trolleys 8 are in contact with one or the other or both of contacts 1-0, 1ll at all times; Itis therefore clear that if the relay 21 is removed thecl-utch magnet 34 isv .energized at all times. If the relay 2l is employed the circuit of said magnet 34 is broken whenever the armature 24 changes position. In view of the fact that the durai other means. Also, while it is designed to use the various features and elements in the combination and relations described, some of these may be altered and others omitted withoutinterfering with the more general results outlined, vand the invention extends to such use. v

Having described my invention, what I claim and desire to secure by Letters Patent casing, of means for supporting the same for free movements in azimuth comprising a supporting element mounted for movement in azimuth andmeans for causing said element'to follow the apparent arc-in-azimuth movements of said wheel, and means associated with said other means for causing a hunting action of said element.

2. In a gym-compass, the combination with the sensitive element, of a mechanical suspension for saidsensitive element, arotary support for said suspension and means for vibrating said support through a predetermined angle with respect to the position of said sensitive' element. n

3. In a gyro-compass, the combination vvwith the sensitive element, of-a rotary supporting element for said sensitive element, a motor connected to said supporting element for rotating it, controlling contacts for said motor adapted to cause normally both a vibrator-y and rotary motion thereof about its vertical axis, and a friction-inertia device connected with said motor adapted to limit 1. The combination with a gyro-wheel and,

the extent of the vlbrations thereof but not to opp-ose a continuons rotation.

4. In a gyro-navigational instrument, .a sensitive element, and a follow up device for relieving the sensitive element of the work necessary to cause apparent arc-in-azimuth movements of said element device, including a motor for driving said device, controlling contacts between saiddevice and element, and a relay in the electrical connections between said contacts and motor. adapted to prevent the motor from becoming locked.

Inv al gym-navigational instrument, a sensitive element, a follow-up device for relieving the sensitive element of the Work necessary to cause a parent arc-in-azimuth movements of the sensitive element, including a motor for driving said device, and a friction-inertia mass connectedf to said motor.-

6. In a gyro compass a sensitive'element, a Vfollow-up support for said element, an alarmv and alarm contacts connected to said element and support adapted to excite said alarm upon the angle between said parts exceeding a predetermined value. i

7. In a navigational instrument, a sensitive element, a follow-up support, for said element, electrical means for driving .said

support and an alarm so connected with said means that a signal is given upon Vfailure of said means t0 operate.

, 8. In a navigational instrument, a sensitive element, a follow-up support'for said element, electrical means for driving. said support,la source of electrical supplr therefor, an alarm, contacts connected to said element and support, adapted to be closed upon the angle between said parts exceedinga predetermined value, other contacts adapted to be closed upon failure of the supply source for said electrical means,

vboth sets of contacts being arranged to actuate said alarm.

9. Ina navigational instrument, a sensitive element, a follow-up support for said element, electrical means driving said support, contacts connected to saidelement/and support, ada ted to be closed upon the angle between sai parts exceeding a p-redetermined value, other contacts adapted to be closed upon failure of the supply source for .said electrical means, and an alarm in cir* cuit with both of sets of contacts.

l0. In a navigational instrumen/t, a sensitive element, a follow-up support for said element, electrical means driving saidsupport, contacts connected to said element and support, adapted to be closed upon the angle between said parts exceeding a predetermined value, other contacts adapted to be closed upon failure of the supply source for said electrical means, an alarm in circuit with said contacts and a relay interposed' in the circuit whereby the alarm will 130 continue to ringwhen once started until the and a cooperating contact for each pair A:mounted so' as to receive relative movement relay is reset.

11. In a navigational instrument, a sensitive element, a follow-up direction indicating member ,for said element, Ielectro mechanicalmeans for driving said member, and automatic means for disconnecting said means mechanically from said member upon failure of the supply current for 'saidmeans. i 12. In a navigational instrument, a sensitive. element, a follow-up support for said element, limit stops and electric contacts element, a rotary support for said element, a plurality of pairs of. reversing contacts betweensaid element and support, a motor in circuit with said contacts and geared'to .saidsupport for maintaining it in a cen- .'tralized position between said stops, and' automatic means for disconnecting said'motor from said support on its failure to opcrate.'

13; Ina navigational instrument, a sensitive element 'a follow-up supportfor said between said element and support, a motor in'circuit with-said contacts and geared to. said support forv maintaining it ina centralized position between said stops, and auto-A matic means for disconnecting said motor from saidsupport, vand for sounding an alarm on lfailure of the motor.

14. In a precision instrument, a sensitive element, a rotary support for'said element, a plurality ofy pairs of reversing contacts andcoperating contacts mounted so as to' vreceive relative movement by the relative movement of, said element and support, means" controlled by said contacts for c ausing said vsupport to hunt continually the positionI of the element, and means for varyingthe amplitude of the hunting action.

15. -In a precision instrument, a sensitive element, a rotary support forsaid element,

al plurality of pairsof reversing contacts .and coperatingcontacts mounted so as to receive relative movement by the relative movement of said element 4and support,

means controlled by said contacts for cau'sing said support to s hunt continually the position ofthe element, and means for shifting the relative position of said pairs of.-

contacts whereby the amplitude of the hunting action is varied.

16. In'l a precision instrument, a sensitive element, a rotary support for said element,

apair of reversing contacts and a coperating contacttherefor mounted so as to receive relative movement by the relative movement .of said` element and support, a

relay in circuit with said contacts and a reversible motor circuit with said relayand connected to said support whereby said positionof theelementi f 1-7. In a precision instrument, a sensitive element, a rotary support' for. said element,

supportis caused to, hunt continually the a plurality of pairsiof reversing contacts tude of the hunting action is adjusted.

18. In a precision instrument, a sensitive and a coperating contact for each pair mounted so as to receive' relative movement.

by lthe relative movement of said element and support, motive means controlled by a pair of lsaid contacts for causing said supportto hunt continually the position of the element, and other motive means controlled melement, limit stops and electric contacts by another pair of said fcontacts. for transi mitting the" angularposition of the support toa repeating instrument without transmitting the hunting.

19. In navigational apparatus, the combination `with la power driven vibratory device, and a repeating instrument,l of means for varying the amplitude of the vvibrations of'said device and of transmitting means a c .tuated from said device for controlling said repeater, comprising a plurality of movable contact members and a movable brush member, lone of said movable members being primarilylactuated from said device', while the votheris' a follower, a tapering dead sectionand a detachable relay for normally controlling -said motor, directly, in circuit with said contacts,- and means for automaticallyv breaking the relay circuits and for forming a direct circuit between said motor and con-- tacts, on said relay p tached from the instrument.

eing physically de Amotor for driving Said device, controlling contacts between said device and element,

iisy

21.' IiialgyroV compass, an azimuth movy able unit, a contact member connected there- -withsofas to :be 'moved thereby, a.coperat ing contact member, contacts borne by said members, a motor actuated from said contacts, a ltransmitter driven thereby, a-nd a` repeater motor actuated from said transmitter and-'connected to said second member to cause it to .follow said firstv member. 22. In a gyro compass, a sensitive element,

45 .f'ivhen supplied With normal current yfrom said supply` y a follow-up support therefor, coperating 'contacts connected to .each of said members,v

a motor actuated afrom said contacts and connected to drive said support, a second motor, a transmitter driven thereby, a repeater motor actuated from said transmitter, and a second setof cooperating contacts having parts operatively connected respectivelyto said -supportand said repeater inotor, said second motorbeing actuated from said second conta-ct set.'-,

23. In a gyro compass,fa sensitive element, a follow-up support therefor, a motor con,A nected 'to drive said support, a second moi toria transmitter driven thereby, a repeater motor actuated from' said',` transmitter, a plurality of contacts .whosev relative position is cont-rolled by two of said motors, said -second motor being actuated from said oo n- 24'. Invr a precision instrument, a sensitive I. element, a rotatable support therefor, a contact member conneted with one of the parts named, cooperating reversing contacts 'on the other of said parts, a relay in circuit with said contacts comprising a pivoted armature, a nairof contacts thereon on` ,opposite sides ofv the pivot; coperating contacts therefor, electromagnetic `means for oscillating the' armature `as a' circuit is closed .through one or-theotherof the lreversing (contacts, and' agreversible motor-in circuit with-.the relay contacts.

25, "In a navigational instrument, a seiisitive element,` a,follower-up,support for said'element,' limit stops Vand' electric contacts between said element andjsupport, a motor in circuitv with said lcontacts and geared to said support for maintaining it in Aascenti'ali'fledA posit-ion between said stops, Va' sourceofsupply for said motor, a clutch "in the connections between the motor and the support, means for normally holding tive elemeii i the fclutchgdisconnected v,and electro-magnetic meansadaptfed to hold theclutch closed ollovv-up directionindicating'member,"limit,stops and' electrical contacts bet-Ween saidlelement and member,-

anda *motor in circuit .with vsaid contacts and connected to said member, whereby said membermay be turnedf-directly by the sensitive element on failure 'of the motor.

27, In a navigational' instrument, a sensiltive element, a follow-up member, limit stops and electrical contactsb'etween said element and member, a transn'iitting device driven bysaid member adapted to control a repeating instrument, and a motor in circuit ivith said conta-cts and connected to said member, whereby ,said member and its transmitter may be turned vdirectly-by the sensitive element on failure of the motor.

.igatioiial instrument, a sensi- A stops and electrical contacts between said element and member, a transmitting device driven by said member adapted to control a. repeating instrument, a motor in circuit with said contacts and connected to said member, and automatic means for disconnecting said inotoi' from said member on its failure-to operate. l

The 4combination with a master indicator, of atransinitting device comp-rising .iiiovablel reversing contact members, a movable br lier of sai'drvmeln-bers being adapted-to be fdrven from ythe master indicator, a reversivotor iii-circtii-ttvith saidcontact inembers-and brush-iineinber, and astep-by-step transmitter connected to said'reversible inotor, said repeater motor being in circuit-With isaid transmitter. A

30, In naviga-tional apparatus, a master direction indicator, la pair of-reversing. contacts and a ycooperating brush, one of said parts heilig connected so as to lbe moved by the apparent arc-in-azimut-h movements of' the indicator, a reversibleniotor in circuit .with said parts, a plurality .of transmitters driven by said-motor at diferent speeds adapted to actuate step-bystepjiepeater instrumentsat different speeds, and a step-i337*-` step repeater motr connected with the other of said parts and in circuit with the higher speed transmitter.

5 nation with a vibratory Jfollow-np device, and a repeating instrument, of transmitting means actuated from said device for controlling said repeater, comprising a pluiality of movable, contacts and a movable brush',

ush Ymember, a repeater motor conone of said movable members, an-A 31. Innavigational apparatus the combi-.

one of said movabledevices being primarily ;actu'atedfrom said device, While the-'other is ajfollower and a tapering' dead section bet-Ween'said contacts, said brush being transversely adjustable.Wherebyithe true readings of the device may `be transmitted' without the vibration. j Y f 32. The combina-tion vitha master instrument, of a transmitting device comprising movable reversing contacts, an insulated sec tion of predetermined 'breadth .separating said contacts, aniovable brush, a repeater' .motor connected to one of said movablel members, anotherof said membersbeling' adapted to be" driven from `the, master instrument, a reversible :motor in circuit with said con- .tacts andf brush, and av step-by-step transmitter connected to'said motor, said repeater motor being incircuit Withs'aidtransmitter.

33. In angle measuring apparatus, in combination with a masterindicator which is normally in' al state of constant Vibration, of

a repeating instrument, and meansv operated r by Said. master indicator for causing said repeater to follow only the angular movements of. the master which exceed the ncrmal extent of its vibrations.

34. In combination, a master compass, Ya

transmitter connected to said master com` pass, a receiving instrument electrically connected to said. transmitter, a source .of E. M. I". for energizing said receiving instrument and means for giving a signal on failure of said source. i

y 35. In a gyro-compass, a gyrosc'opic member, ajsecond member, supporting and guiding means .for supporting said gyrosco-pic member on said second memberfor turning with respect-thereto, and means for imparting to said members continuous relative vibrations.

'36.' In a-gyro-compass', a gyroscopic mem- I ber, a second member, supporting 'and guiding means for supporting said first member lon said second member for turning with re# spect thereto, reversible 'motiveineans oonnected to said second member, vreversing contacts carrled bysaid two members for operating said motive means and means for causing sald motive means to continually,

reverse,

37. In a gyro-compass, a gyroscopic member, a second memben supporting and'guiding means for supporting said irst member on said second member for turning with respect thereto, vmea-ns for impartin to said members'continuous relative vibrations, and l means whereby the extent or amplitude of the vibrations may be varied.

38. In a navigational instrument, the combination with a sensitive element, a followup device for supporting the'same, an indicating means on said device, and means 4for imparting to said device a vibratory movement.

39. In gyro-navigational'apparatus, the

vcombination With a gyroscopic element,- a

follow-up device,` a transmitter driven by said device,"v a repeater system actuated.

thereby and means .for imparting to said vdevice-and transmitter continuous vibratory'.v

movements.- V v 40. In a gyro-compass, agyroscopi member, a follow-up or repeating indicating de-l vice, and means forimparting to said' device vibratory motion in addition to its normal motion in following the movements of said member.

'41. In-a precision instrument, al movable Vvibrations. Y

sensitive element, a supporting follow-up element therefor, and means for imparting to one of saidele'ments'continuousrelative 42. A fri'ctionlessfsupport forr sensitive elements' cmprising a bearing'frame, a support journaled thecnimisensitive element supported and guided for rotation on said support "and means for imparting'relative vibrations to-saidsupport Vand element.

" 43. In combination, a directionally sensitive element, a relatively movable' support, a

bearing between said element and support,

one part of said bearing being fixed to said element, the other part of said bearing bei ing ixedto said supportand means for imf i parting relative vibrations to'said'element andfsupport.-

44. In combination, a directionally sensitive navigating instrument, a remotely located repeating instrument controlled thereby .and meansV for periodicallyreversing said instrument although the-course is unchanged.

45. In a gyroscopic compass for ships, the combination with a power source of electrical supply, la gyroscopic rotor driven therefrom, a follow-up motor also driven theresaid motor.

47. In a gyrcompass, a directive element, a support therefor, said element and support being relatively movable, means for imparting thereto continuous relative vibrations, a repeater compass, and means operated by the gyro-compass vfor causing said repeater to reproduce onlynthe directive movements of the elements.

In testimony whereof, I have' signed my name to this specification in the presence of two subscribing Witnesses, -this 21st 'day ofA January 1915.

. ELMER,A. SPERRY. Witnesses:

P. L. ANDERSON, ETHEIl N. BAUMGARTNER. -v 

